SHARE-BASED COMPENSATION - RSU Activity (Details) (USD $)	9 Months Ended
	Sep. 30, 2012 number	Sep. 30, 2011
Number of Restricted Stock Units [Roll Forward]
RSUs beginning	1,860,577
RSUs awarded	290,556
RSUs released	(358,131)
RSUs forfeited	(20,790)
RSUs ending	1,772,212
Weighted Average Purchase Price RSUs	$ 0
Weighted Average Remaining Contractual Term (Years) RSUs	1.2
Aggregate Intrinsic Value RSUs	$ 12,157,374
Number of RSUs vested and expected to vest	1,654,227
Weighted Average Purchase Price of RSUs vested and expected to vest	$ 0
Weighted Average Remaining Contractual Term (Years) of RUSs vested and expected to vest	1.2
Aggregate Intrinsic Value RSUs vested and expected to vest	10,751,208
Number of RSUs exercisable	86,996
Weighted Average Purchase Price of RUSs exercisable	$ 0
Weighted Average Remaining Contractual Term (Years) of RUSs exercisable	0.0
Aggregate Intrinsic Value RSUs exercisable	596,793
Weighted average remaining recognition period in years	1.9
Unamortized compensation expense, net of estimated forfeitures	6,692,351
Other Options Disclosure [Abstract]
Intrinsic value of options exercised	446,000	520,000
Tax benefit from options exercised, before impact of valuation allowance	169,000	198,000
Cash received from exercise price of options exercised	$ 120,000	$ 69,000